Electric hair dryers have become extremely popular consumer products in recent years and are available in a variety of shapes and operational types, particularly hand-held pistol grip types and others. For reasons of sales promotion and to provide more efficient drying of wet hair, manufacturers have tended to increase the power of either the blower component or the heating component or both in these dryers. Another objective has been to produce the high heating or air flow capabilities in smaller housings, and additionally to achieving higher operating efficiencies and safety and to produce these devices as economically as possible.
Even with the developments mentioned above and improvements in hair dryer design and capability, there has been a persistent disadvantage with these high powered devices, in that the user's hair is blown out of place or otherwise so disturbed that the users often must return to the old slower dryers.
An attempt to provide hair drying capability with reduced air velocity has been made with the development of new dryers which have a quartz tube heating element, preferably in combination with a reflector for producing a substantially high quantity of directed radiant heat to the user's hair with little or no air flow required. In practice it has been found that a very small blower unit is helpful or necessary to move the air about inside the housing of a quartz tube dryer, thereby cooling and preventing the housing components from overheating due to the extremely high-temperature quartz tube. Additionally the small blower will produce a moderate air flow which has the normal hair drying effect.
With these quartz tube dryers the problems of wind blown hair are substantially reduced; however it has been found that the quartz tube elements are highly susceptible to breakage should the device be accidentally dropped or banged against a rigid surface. Breakage of such hair dryers can be very dangerous to users because the glass tubes shatter producing a multitude of glass splinters with the obvious kinds of consequences. These types of concussions easily happen with consumer products of this type which are frequently moved into and out of storage areas such as drawers and closets, are carried around between rooms, and are carried in luggage during travel.
These tubes are particularly fragile for various reasons: the tube's glass wall construction is not reliably of uniform thickness, thus resulting in randomly located weak areas; traditional soft type cushioning, shock mount materials and techniques are not feasible, because of the intense high temperatures reached; and traditional ceramic support structures which can easily tolerate the heat are rigid, the lack of resilience resulting in a very substantial amount of breakage of these tubes during normal use or when subjected to intentional impact. The above-mentioned inconsistency in wall thickness of the tube worsens the problem since it is not feasible to locate and situate the stronger portions in contact with the mounts, and the weak portions may fail due to concussion anyway.
The breakage problem has been sufficiently serious and so difficult to solve, that regulating agencies in the United States, such as the Underwriters Laboratory, have been denying approval to these prior art and known products on the grounds that they are unsafe, because they cannot withstand the standard drop test, whereby the product is dropped three times onto a hardwood surface from a three foot height, with the product being dropped in random orientations; these drop tests are conducted at both manufacturing locations and at the Underwriters Laboratory itself under more controlled conditions. The prior art devices continue to fail these tests with both straight and circular quartz heating tubes. Without the Underwriters Laboratory approval these products cannot be marketed in most major markets in the United States, representing, in effect, a product that is physically producible but not practical for manufacture because sales are prohibited and/or consumers would ultimately be dissatisfied with the high breakage factor.
The present invention provides a new construction for mounting and supporting the quartz glass heating tubes in a manner which has been found to be reliably safe for preventing breakage under both normal use and under the above-mentioned standard drop test. Accordingly, the invention makes it possible for new dryers to utilize the quartz glass heating tubes and provide the benefits available therewith on a feasible and manufacturable basis. This is a significant invention, in that it will make possible the development of a whole new family of hair dryers and accordingly a whole new and long-needed sub-market.